Zircon U-Pb geochronology, geochemical characteristics and geological significance of the Chakeng granite porphyry, northeast Jiangxi Province

The scheelite mineralization was found in the Chakeng granite porphyry and its surrounding rocks in northeastern Jiangxi Province. In order to ascertain the relationship between the tungsten mineralization and granite porphyry and pursue its metallogenic potential, the zircon U-Pb isotopic dating, geochemical and petrographic studies of granite porphyry were carried out. The results show that the Chakeng granite porphyry is 152~153 Ma in age, characterized with high silicon (content of SiO₂ is 74.62％~76.09％), rich alkali (content of Na₂O+K₂O is 7.14％~8.55％) and kalium (content of K₂O is 4.95％~5.69％), as well as strongly peraluminous (A/CNK=1.17~1.39, averagely 1.3); the trace elements are relatively enriched in Rb, U, K, and deficient in Ba, Sr, P, Ti; The total content of rare earths is (62.52~75.13)×10^-6, and (La/Yb)_N=3.73~12.16, with an average value of 7.81.The fractional distillation of light and heavy rare earth elements is obvious, and the light rare earth elements are relatively enriched, with moderate negative Eu anomaly (δEu is 0.55~ 0.82). The W content in the Chakeng granite porphyries is (8.80~160)×10^-6, with an average value of 51.16×10^-6, 15 times of the average tungsten content of the granites in South China, indicating that the granite porphyries in the Chakeng area have metallogenic potential of porphyry-quartz vein-type tungsten deposit.